Switching devices are typically data link layer devices that enable multiple network devices to communicate with each other or enable physical network (e.g., local area network (LAN) or wide area network (WAN)) segments to be interconnected into a single larger network. In the most general sense, switching devices transport data in the form of frames between input/output (I/O) ports. A frame is a logical grouping of information sent as a data link layer unit over a transmission medium. Each frame typically includes data payload encapsulated between header and trailer information. Terms like cell, datagram, message, packet, and segment are also used to describe logical information groupings at various layers of the OSI reference model and in various technology circles. As used herein, the term “frame” should be understood in this broadest sense, and can be defined to encompass other terms such as cell, datagram, message, packet, segment, etc.
Switching devices often employ switching fabrics that have multiple I/O ports coupled to each other. Users typically require that each switching device operate as quickly as possible in order to maintain a high data throughput rate. Unfortunately, limitations within the switching device hardware can impair the ability of the switching device to operate as quickly as possible. For example, changes in configuration of the switching device can lead to there being an inability to completely specify each destination port using predefined internal addressing information, causing the egress line card to either flood the frame through all output ports (including ones that did not actually need to output that frame, which may adversely affect other traffic being output from those output ports) or perform an additional lookup for the frames at the output ports, leading to a decrease in performance.
While the invention is susceptible to various modifications and alternative forms, specific embodiments of the invention are provided as examples in the drawings and detailed description. It should be understood that the drawings and detailed description are not intended to limit the invention to the particular form disclosed. Instead, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.